Electronic monitoring systems, shipment container monitoring systems and mehtods of monitoring a shipment in a container

ABSTRACT

A shipping container has a passive radio antenna element having internal and external antennas. A connector spanning the wall joins the two antennas. An internal communications device is disposed within the container and an external communications device is disposed external to the container. Another shipping container has a repeater element having internal and external antennas. A repeater unit spans the wall joining the two antennas. A communications device is disposed within the container and another communications device is disposed externally. RF signals are re-radiated by the antennas. Methodology includes emitting RF signals from a communication device disposed at a first location, receiving the signals through an antenna comprised by an antenna element, and re-radiating the signal from a second antenna comprised by the element, where the element spans the wall of a shipping container. The re-radiated signal is received by a second communications device disposed at a second location.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.12/631,643, filed Dec. 4, 2009, to become U.S. Pat. No. 7,978,147, whichis a continuation of U.S. patent application Ser. No. 11/674,966, filedFeb. 14, 2007, now U.S. Pat. No. 7,629,943, the disclosures of which areincorporated herein by reference.

TECHNICAL FIELD

The technical field is electronic monitoring systems, shipmentmonitoring systems and methods of monitoring a shipment.

BACKGROUND OF THE INVENTION

Electronic monitoring and control devices are utilized for purposes suchas monitoring of shipment containers and may be utilized for detectingthe presence of hazardous content such as radiation and/or explosivedevices. Theoretically, interfacing of communication equipment to otherelectronic monitor equipment outside the shipping container may be doneone of two ways: either by utilizing wired interfacing or by wirelessinterfacing. Due to the immense number of containers to be monitored,however, it is strongly preferable to utilize wireless interfacing.However, wireless interfacing can be problematic due to the use ofmetal-walled shipping containers such as steel inter-modal containersand aluminum airline freight containers, which reflect electric fieldsthat are typically used in VHF, UHF and MW radio transmissions. Becausethese containers are closed after loading with freight, attempts tocommunicate by radio to and from radio equipment located within thecontainer by radio equipment located outside the containers can bedifficult. Transmission from equipment inside the container simplyreflects from the metal floor, ceiling and walls, never reaching outsidethe container. Transmission from equipment outside the containerreflects from outer metal of the container never reaching to the radioreceiver located on equipment inside the container. Accordingly, itwould be advantageous to develop methods and apparatus for enablingradio transmission into and out of metal containers.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram of a wireless communication system embodiment.

FIG. 2 is a diagram of another wireless communication system embodiment.

FIG. 3 is an enlarged fragmentary diagram showing a portion of anotherwireless communication system embodiment.

FIG. 4 is a block diagram of a component of the wireless communicationsystem of another embodiment.

FIG. 5 is a diagram of another wireless communication system embodiment.

FIG. 6 is an enlarged fragmentary diagram showing alternative powersource placements for the embodiment depicted in FIG. 5.

DETAILED DESCRIPTION

Various systems and methods are disclosed for monitoring freightshipment utilizing a passive radio antenna element. Specifically,embodiments of the invention are described with respect to use inconjunction with metal shipping containers. It is to be understood,however, that the systems and methodology described can be utilized forother security and monitoring purposes and for containers which comprisein whole or in part materials other than metal.

Embodiments of the disclosure utilize a passive radiator, a radioantenna element which does not have any wired input. The passive radioantenna element absorbs radio waves radiated from another active antennaelement in close proximity and re-radiates it. An example of a systemutilizing the passive radio antenna element is shown in FIG. 1. Anelectronic shipping monitoring system 10 is shown. A corner fragment ofa metal-walled shipping container 12 is shown having a vertical wall 14.Container 12 can be, for example, a metal container for transport byair, sea, rail and/or truck.

Vertical wall 14 has a first surface 16 disposed within container 12 andan opposing second surface 18 which may be an exterior wall surface ofthe container. An opening 19 is shown passing through wall 14 near anupper corner of the container. It is to be understood that the depictedlocation of opening 19 is for purposes of illustration purposes only andsuch can be disposed at any desired location throughout the container,penetrating any portion of container forming a barrier between theinterior and exterior thereof, including any exterior wall, junction ofwalls, door, lid, etc.

A passive radio antenna element 20 is shown disposed spanning wall 14through opening 19. Passive radio antenna element 20 may include a firstantenna 22 disposed proximate interior wall surface 16 and a secondantenna 24 disposed proximate exterior wall surface 18. A connector 26may span wall 14 through opening 19 to connect first antenna 22 withsecond antenna 24. Opening 19 may be configured to be relatively smallin order to maintain security of the container's contents, structuralintegrity of the container and to keep out the elements. Any gap betweenconnector 26 and wall 14 within gap 19 may be sealed with an appropriatenon-conducting sealant such as silicone.

System 10, in an embodiment, may further include an externalcommunication device 30 at a first position outside container 12 and mayhave an active antenna 32. An internal communication device 40 may bedisposed at a second position within the container and may have anactive antenna 42.

Utilizing the embodiment of the invention shown in FIG. 1, methodologyof the invention can be performed by emitting an RF signal from a firstlocation, re-radiating the RF signal through the passive antenna andreceiving the re-radiated signal at a second location. Specifically, asshown in FIG. 1, an RF signal may be emitted from a transmittercomprised by external communication device 30 via active antenna 32. Thesignal can be radiated to be received by antenna 24. Such signal canthen be re-radiated from antenna 22 and the re-radiated signal can bereceived by a receiver comprised by internal communication device 40 viaactive antenna 42.

In some embodiments, one or both of the antennas 22 and 24 are supportedby the wall 14 or are elsewhere supported by the container. In someembodiments, the connector 26 is insulated relative to the wall 14 toavoid electrical coupling with the wall 14. For example, the entirelength of the connector 26 may be insulated, the portion through opening19 can be insulated, or some portion of the length of the connector 26may be insulated. If some portion of the length of the connector 26 isinsulated, that portion would be positioned in the opening 19. In someembodiments, the connector 26 is not insulated but the opening 19 has aninsulator providing electrical insulation, and the connector passesthrough the insulator. In some embodiments, the opening 19 is sealedrelative to the connector 26, e.g., with non-conductive material, afterthe connector 26 is caused to extend through the opening.

In some embodiments, the device 30 is a reader and the device 40 is anRFID tag. More particularly, the container may contain inventory and oneor more RFID tags are supported by the inventory. RFID tags may besupported on individual items of inventory, or on pallets or othergroupings of inventory. In some embodiments, an RFID tag may be includedsolely to identify the container 12.

One way to track objects is by affixing RFID tags to objects or groupsof objects, and interrogating the RFID tags with an interrogator orreader to determine which objects are present in any particularlocation. RFID tags may be provided with unique identification numbersor codes in order to allow a reader to distinguish between multipledifferent tags. In some embodiments, the antennas 22 and 24 are used toenhance communications between RFID tags inside the container and areader outside the container. In some embodiments, antennas 22 and 24may be used to enhance communication between an interrogator or reader30 and a transceiver 40 external to the container, where the transceivermay be connected to additional external devices (not shown) such as acontroller, second reader, or network interface.

In some embodiments, the device 40 is an RFID tag that uses magneticcoupling for power. The devices may be entirely passive (have no powersupply), which results in a small and portable package.

In some more particular embodiments, the device 40 is an RFID tag thatcomplies with EPCglobal Class 1, Generation 2 standards. EPCglobal is astandard setting organization that is developing standards forelectronic product codes to support the use of RFID technology. One oftheir standards, called Class 1, Generation 2 (also known as “Gen 2”)applies to passive RFID systems.

In other embodiments, the device 40 is an active RFID tag, whichincludes its own source of power, such as a battery.

In some embodiments, the device 40 is an RFID tag that includes (seeFIG. 4) a processor 48, and a transceiver coupled to the processor 48.In these embodiments, the device 30 is a reader. The RFID tag respondsto commands issued by the reader and received by the transceiver 50. Theprocessor 48 processes received commands and the processor 48 causes thetransceiver 50 to transmit a reply. In some embodiments, the reply isbackscattered. Memory 52 is also included and, while shown as a separateblock in FIG. 4, could be included in the processor 48 in someembodiments. Power is supplied by a power source 54 which may be amagnetic coil, battery, or other type of power source.

Referring next to FIG. 2, such shows an alternative embodiment where aninitial RF signal is emitted from an internal communication device 40 avia an active antenna 42 a. The initial RF signal is received by firstantenna 22 and is re-radiated by second antenna 24. The re-radiatedsignal is received by an external communication device 30 a by way ofactive antenna 32 a. Accordingly, the passive radiator systems of theinvention may be utilized either for receiving a signal emitted fromwithin the container and re-radiating the signal to a receiver locatedexternal to the container, or alternatively may receive an externalsignal and re-radiate the signal to a monitoring device within container12.

Further embodiments of the present invention are discussed withreference to FIG. 3. As shown in FIG. 3, passive antenna element 20 mayhave a first antenna 23 and a second antenna 25, each of which may bepatch antennas. Alternatively, the first and second antennas may be ofdiffering types (not shown). For example, either external antenna 25 orinternal antenna 23 may be a dipole antenna while the other antenna is apatch antenna. Alternatively, each may be a dipole antenna. Antennas 23and 25 may have the same polarization or can have differing polarization(e.g. linear-linear, circular-linear). The two antennas can have thesame orientation or can have differing orientations (e.g. up-up,up-sideways). The two antennas can have the same gain or can havedifferent gains. Further, the two antennas can have the samedirectionality or can have differing directionalities. As further shownin FIG. 3, connector 26 can be configured to have at least one coaxialconnector 27. In particular instances, connector 26 will have a coaxialconnector at each end (not shown).

In some embodiments, the connector 26 is insulated relative to the wall14 to avoid electrical coupling with the wall 14.

One or more antenna housings 44, 46 can be provided to cover all or aportion of antennas 23 and 25. Such can be mounted to interior surface16 and/or exterior surface 18. Housing 44, 46 may be fabricated of amaterial which does not interfere with RF energy. In particularinstances, one or both of housings 44 and 46 may be configured tosimulate a vent cap or other structure to render camouflage for theantenna. When such camouflage is desirable, to mount the passive antennaand corresponding housing may be mounted relatively high on thecontainer wall to better simulate a vent cap appearance.

An additional embodiment is described with reference to FIGS. 5-6.Referring initially to FIG. 5, a repeater system 10 a is shown having arepeater element in place of the passive antenna element described inprevious embodiments. A repeater unit 55 may be disposed betweenantennas 22 and 24 thereby physically connecting the two antennas tospan wall 14. Repeater 55 may be configured to allow signals transmittedfrom both internal communications device 40 and external communicationsdevice 30 to be retransmitted by antennas 24 and 22 respectively.Repeating system 10 a may thereby serve as a relay system tobi-directionally reradiate from transmitting antennas 22 and 24. Thevarious antenna types, configurations, housings, etc. described withrespect to the passive antenna communication systems above may beequally employed with respect to the present repeater system.

FIG. 6 illustrates various positions at which a repeater power supplymay be located. Such power supply may be a battery, for example, and maybe located at an internal location 62 relative to the shipping containeror may be external 60 relative to the shipping container. Alternatively,a battery 58 may be provided within the repeater unit 55 along withrepeater circuitry 56. Alternative electric connection routes for eachof the three battery positions are illustrated by dashed lines.

In compliance with the statute, the subject matter disclosed herein hasbeen described in language more or less specific as to structural andmethodical features. It is to be understood, however, that the claimsare not limited to the specific features shown and described, since themeans herein disclosed comprise example embodiments. The claims are thusto be afforded full scope as literally worded, and to be appropriatelyinterpreted in accordance with the doctrine of equivalents.

1. An electronic monitoring system, comprising: a container having awall comprising a first side and an opposing second side; an externalcommunications device disposed external to the container; an internalcommunications device disposed within the container; and a passive radioantenna element comprising a first antenna disposed within thecontainer, a second antenna disposed external to the container, and aconnector spanning the wall and joining the first and second antennas.